Dunnage door for cargo box

ABSTRACT

A dunnage door for use with a cargo box adapted to be partially filled with cargo from the back or the bottom toward the front or the top on which the door is assembled in which the interior of the door is provided with normally collapsed expansible means adapted to be expanded to fill the space between the door and the cargo to prevent movement of the cargo within the box during shipment.

United States Patent 1 Frieder, Jr.

[451 May 15, 1973 [54] DUNNAGE DOOR FOR CARGO BOX [75] Inventor: LeonardP. Frieder, Jr., Waverly,

[73] Assignee: Gentex Corporation, New York,

[22] Filed: June1,l97l

[21] Appl. No.: 148,845

[52] US. C1.,....220/85 B, 206/D1G. 30, 105/369 BA [51] Int. Cl. ..B65b3/00 [58] Field of Search ..220/85 B; 105/369 BA; 206/DIG. 30

[56] References Cited UNITED STATES PATENTS 2,907,580 10/1959 Tietig..105/369 BA X 3,243,822 4/1966 Lipkin ..105/369 BA X 2,764,950 l()/1956Finnell .,lO5/369BA 2,834,606 5/1958 Bertrand ..105/369 BA 3,192,8797/1965 Pier ..l05/369 BA 3,514,151 5/1970 Hacker ..105/369 BA FOREIGNPATENTS OR APPLICATIONS 1,173,782 10/1958 France ..220/85 B 1,917,90911/1969 Germany ..220/85 B Primary Examiner-M. Henson Wood, Jr.Assistant ExaminerJohn J. Love Attorney Shenier and OConnor A dunnagedoor for use with a cargo box adapted to ABSTRACT be partially filledwith cargo from the back or the bottom toward the front or the top onwhich the door is assembled in which the interior of the door isprovided with normally collapsed expansible means adapted to be expandedto fill the space between the door and the cargo to prevent movement ofthe cargo within the box during shipment.

3 Claims, 3 Drawing Figures PATENTEDHAYI 51m SHEET 1 OF 2 INVENTOR. Leonara P Friec/erJr MXM H TTORNE Y5 DUNNAGE DOOR FOR CARGO BOXBACKGROUND OF THE INVENTION There have recently been developed in theprior art cargo boxes which are readily erected and disassembled andwhich are especially adapted for use in connection with aircraft cargo.It has been discovered that the available space within an aircraft ismore efficiently used and cargo-handling operations are moreexpeditiously carried out if articles to be shipped first are stowed inboxes of a standard size and then the boxes in turn are loaded onto theaircraft. Preferably these boxes should be reusable and have a longlife. They are disassemblable so as to be able to be stored and shippedflat and are readily erected at the point at which they are to be used.It will be apparent that for most efficient manufacture and use of suchboxes they are made in standard sizes.

In most instances the cargo to be shipped in aircraft is loaded in theboxes and at least the last box has some space left therein between thefront or top of the box and the opening over which the last side or doorof the box is to be assembled. Such is the case also wherein thearticles to be stowed in a particular box do not completely'fill thespace therein. In order to prevent damage to articles in partiallyfilled containers during shipment the container space must be completelyfilled. In the maritime field the material which is used to fill suchspaces is known as dunnage. While in the case of an aircraft cargo boxthe excess space could be filled with many different materials, suchmaterials create a problem of disposal at the point of termination ofthe cargo and require that such materials be stored so as to be at handat the point at which the box is loaded.

I have invented a'dunnage door for a cargo box which overcomes theproblems outlined hereinabove. My dunnage door can readily be actuatedto fill the excess space in a cargo box. It will take up such space overa wide range of partial fillings of the container. It does away with thenecessity for storing and handling loose dunnage material. It furthereliminates the problem of disposing of such loose used dunnage materialat the termination point. It is relatively simple for the resultachieved thereby. It takes up very little extra space over that occupiedby the door of the cargo box. It permits the cargo box to be stowed flatfor storage and shipment when empty.

SUMMARY OF THE INVENTION One object of my invention is to provide adunnage door for a cargo box to take up excess space in the box overthat occupied by the cargo.

Another object of my invention is to provide a dunnage door for a cargobox which does away with the necessity for storing loose dunnagematerial.

A further object of my invention is to provide a dunnage door for acargo box which eliminates the prob lem of disposing of loose dunnagematerial.

Still another object of my invention is to provide a dunnage door for acargo box which permits the disassembled box to be stored and shippedflat.

A further object of my invention is to provide a dunnage door for acargo box which can take up a relatively wide range of space within thebox. 7

Other and further objects of my invention would appear in the followingdescription.

In general my invention contemplates the provision of a dunnage door foruse with a disassemblable cargo box adapted to be erected and. partiallyfilled with cargo from the back or bottom towardthe front or top andover which the door is assembled in which the inside of the door isprovided with normally collapsed expansible or extendible means adaptedto be actuated to fill the space between the door and the cargo toprevent movement of cargo within the box during shipment. In itscollapsed condition the expansible means lies flat against the insidesurface of the front or top to permit the box to be stored and shippedin flat condition.

BRIEF DESCRIPTION OE THE DRAWINGS In the accompanying drawings whichform part of the instant specification and which are to be read inconjunction therewith and in which like reference numerals are used toindicate like parts in the various views:

FIG. 1 is a perspective view of one form of cargo box provided with mydunnage door.

FIG. 2 is a fragmentary sectional view of the box illustrated in FIG. 1taken along the line 2--2 of FIG. 1.

FIG. 3 is a sectional view of the box illustrated in FIG. 2 taken alongthe line 3--3 of FIG. 2 with parts removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsone form of cargo box indicated generally by the reference character 10with which my dunnage door may be used can be of the general typedisclosed and claimed in the co-pending application of August G.Luisada, Ser. No. 6,855, filed Jan. 29, I970, now U.S. Pat. No.3,655,087 for a Lightweight Knockdown Container. The box shown in thatapplication as well as other various forms of knockdown boxes orcontainers with which my dunnage door may be used comprise a pluralityof panels adapted to be stowed in a stack and to be shipped in thatcondition while being readily erectible at the location at which thecargo is to be loaded. The particular form of box 10 which I have shownin the drawings includes a base 12, sides 14 and 16, a front 18, a back20 and a top 22. As is more fully described in the co-pendingapplication, the base, sides, front and back first are erected withinterlocking elements at adjacent edges and with seals around theseedges. The top panel 22 then is assembled on the container in a mannerto be described to close the box. Other forms of boxes or containers towhich my dunnage door can be applied may be of the type in which all ofthe panels except the front panel 18 are erected before the box isfilled and then the panel 18 is assembled over the open front. In eithercase my dunnage door comprises the last panel to be placed in positionover the container.

In the particular structure which I have shown in the drawings thevarious panels of the box may be of any suitable construction so as toprovide sufficient strength to withstand the loads to which they will besubjected while at the same time being relatively light. For example,each of the panels may comprise a central body portion or core 24 whichis formed from foamed polyurethane resin and which may be reinforced ifdesired. Each of the central bodies is provided with inner and outerskins 26 and 28 of any suitable construction. They may, for example, beresin impregnated glass fabric or aluminum sheet or the like. EAch ofthe panels further is provided with a frame made up of extruded aluminumchannels 30 around the periphery thereof.

As has been pointed out hereinabove the particular container shown iserected by interengaging elements along adjacent edges of the base 12side panels 14 and 16 and front and back panels 18 and 20. Since theseinterengageable means do not per se form any part of my invention theywill not be described in detail. One example of such interengageablemeans is shown in the Luisada application referred to hereinabove. Afterthe portion of the container described above has been erected and whencargo has been placed therein the top 22 is placed over the open top ofthe container. The back edge of the top 22 is provided with an inwardlydirected angle (not shown) which engages a corresponding angle (notshown) on the upper edge of the back in the manner shown in theco-pending application. Respective pairs of angles 32 and 34 along theside edges of the top 22 house gaskets 36 which rest against the upperedges of the sides. Similarly brackets 82 and 84 along the front edge ofthe top engage the upper edge of the front panel 18 to bring a gasket 88into engagement with the upper edge of the front panel. The bracket 84may be formed with a hook 86 making up part of a latch to be describedfor holding the top in position on the box.

The particular form of normally collapsed expansible means illustratedin the drawings which provide dunnage for my cargo box includes abellows-like structure indicated generally by the reference character 40comprising a top piece 42, a bottom piece 44 and intermediate pieces 46formed with central openings 47. These pieces, 42, 44 and 46 may be madefrom any suitable air-impervious material. For example, they may beformed from canvas or the like the surfaces of which have beenrubberized so as to render them impervious to the passage of air.Alternatively any suitable flexible, synthetic, resin sheet material maybe used to form the pieces of the bellows structure 40. 1 connect theouter edges of adjacent pieces by any suitable means. For example, theedges may be stitched and then heat sealed each to the other to providean impervious seal around the edge. Alternatively in some instances heatsealing may be sufficient to provide the required seal. 1 have indicatedthe seals around the outer edges of adjacent pieces by the referencecharacter 48. Similar seals 50 are provided around the inner edges ofeach of the adjacent pairs of intermediate pieces 46.

While I have illustrated a square configuration of bellows it willreadily be appreciated that I may employ any shape which is adapted tohold cargo in position within the boxlO. Openings 47 preferably arecircular.

l secure brackets 52 around the inner surface of top 22 spaced slightlyinwardly from the periphery thereof by any suitable means such as rivetsor the like. One end of each ofa plurality of elastic straps 54, theouter periphery of the top piece 42 and the first intermediate piece 50therebelow all are secured to the brackets 52 at spaced locationstherealong by any suitable means such as by rivets 56. The elasticstraps 54 extend from the rivets 56 through D rings or the like carriedby the pairs of intermediate pieces 50 at the peripheries thereof. Afterpassing through the D rings 58 the other ends of the elastic straps 54are secured to the assembly of the periphery of the lowermostintermediate piece 50 and the bottom piece 44 by any suitable meanssuch, for example, as by rivets 60.

l form the panel 22 and the top piece 42 of the bellows structure 40with an inlet opening 62 which I position a fitting 66 through which theinflating medium such as gas or air can be admitted to the bellows 40.An on-off valve 70 is adapted to be actuated to supply a suitable gasunder pressure to the interior of the bellows structure 40 to expand thesame. This may be achieved from any suitable source. It may be desirableto attach a cylinder of compressed gas 72 to the outside of the top 22by means of a bracket 74. I also provide the top 22 with a relief valvecomprising a housing 76 containing a valve which is urged to closedposition by a spring 80. It will readily be appreciated that if thepressure within the bellows exceeds a force proportional to that of thespring 80 valve 78 moves away from its seat to relieve the excesspressure.

While I have shown the elastic straps 54 for normally urging the bellowsstructure 40 to collapsed condition at which it lies substantially flatagainst the underside of the top 22, I may make the bellows structureitself out of an elastic material which is self-collapsing so asnormally to rest against the under surface of the top 22.

Further while l have shown an inflatable structure which is resilientlyurged to collapsed condition to provide dunnage I might provide anyextensible and re,- tractable structure which normally lies flat againstthe inside surface of the door 22 and which can be actuated so as toengage articles of cargo within the container.

In use of my dunnage door I first erect a container such as thecontainer 10 by joining all of those panels except for the top 22 whichis to form the final closure for the container. The container then isfilled with cargo to a predetermined level such, for example, as thatwhich will be determined by the amount of cargo available or by thesizes of the individual articles. Next the final closure member such astop 22 is secured in place and valve 70 is actuated to supply gas underpressure to the interior of the bellows structure 40 to expand thebellows to move the lower piece 44 up against the cargo in the box tohold it in position against shifting. In the course of shipment if, forexample, the temperature rises to cause the pressure within the bellows40 to increase valve 78 moves away from its seat to relieve the pressureuntil the pressure drops to the desired value. Upon arrival of thecontainer at its destination the operator first actuates valve 70 torelieve the pressure within the container and then removes top 22 andunloads the cargo. The straps 54 pull the bellows flat against theunderside of the top 22 as the fluid under pressure is released from theinside of the be]- lows. Now after cargo is unloaded the container canbe disassembled and the parts stacked so as to permit shipment orstorage without taking up excess space.

it will be seen that l have accomplished the objects of my invention. lhave provided a dunnage door for a cargo box which takes up excess spacein the box. My door prevents shifting of cargo in a partially filled boxduring shipment. it does away with the necessity of storing and havingavailable dunnage during loading. it also eliminates the problem ofdisposing of dunnage at the point at which the container is unloaded. Itis so constructed as to permit a container including the door to bestowed flat. it is simple in construction for the result achievedthereby.

it will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations.

This is contemplated by and is within the scope of my claims, It isfurther obvious that various changes may be made in details within thescope of my claims without departing from the spirit of my invention. Itis, therefore, to be understood that my invention is not to be limitedto the specific details shown and described.

Having thus described my invention, what i claim is:

l. A dunnage door adapted to be assembled over the open end of acontainer partially filled with cargoincluding in combination, a doorbody having an inside surface, a bellows-like structure comprising aninner end piece attached to said inside surface, a plurality ofintermediate pieces forming the side wall of said structure and an outerend piece, said pieces being assembled to enclose an air impermeablespace, a plurality of elastic straps disposed outside said space andaround the periphery of said structure, means for attaching one end ofeach of said straps to said inner end piece,

means connecting the other end of each of said straps to said outer endpiece, means coupling said intermediate pieces adjacent to theperipheries thereof to said straps intermediate the length thereof, saidstraps normally urging said structure to collapsed condition againstsaid inner surface, and means accessible from outside said door forsupplying gas under pressure to the inside of said structure.

2. A dunnage door as in claim 1 in which said means connecting saidstraps to said intermediate pieces comprise rings for receiving saidstraps. I

3. A dunnage door as in claim 2 including a relief valve mounted in saiddoor to provide communication between the inside of said structure andthe outside of said box in response a predetermined buildup of pressurein said interior.

1. A dunnage door adapted to be assembled over the open end of acontainer partially filled with cargo including in combination, a doorbody having an inside surface, a bellows-like structure comprising aninner end piece attached to said inside surface, a plurality ofintermediate pieces forming the side wall of said structure and an outerend piece, said pieces being assembled to enclose an air impermeablespace, a plurality of elastic straps disposed outside said space andaround the periphery of said structure, means for attaching one end ofeach of said straps to said inner end piece, means connecting the otherend of each of said straps to said outer end piece, means coupling saidintermediate pieces adjacent to the peripheries thereof to said strapsintermediate the length thereof, said straps normally urging saidstructure to collapsed condition against said inner surface, and meansaccessible from outside said door for supplying gas under pressure tothe inside of said structure.
 2. A dunnage door as in claim 1 in whichsaid means connecting said straps to said intermediate pieces compriserings for receiving said straps.
 3. A dunnage door as in claim 2including a relief valve mounted in said door to provide communicationbetween the inside of said structure and the outside of said box inresponse a predetermined buildup of pressure in said interior.